package com.example.threaddemo;

import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicReference;
import java.util.concurrent.atomic.AtomicStampedReference;

public class ABADemo {
    static AtomicReference<Integer> atomicReference = new AtomicReference<>(100);

    static AtomicStampedReference<Integer> atomicStampedReference = new AtomicStampedReference(100,1);

    public static void main(String[] args) {
        System.out.println("ABA问题的产生----------------");
        new Thread(() -> {
            atomicReference.compareAndSet(100, 101);
            atomicReference.compareAndSet(101, 100);

        },"t1").start();

        new Thread(() -> {
            try {
                TimeUnit.SECONDS.sleep(1);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            System.out.println(atomicReference.compareAndSet(100, 101) + " t2的修改 " + atomicReference.get());
        },"t2").start();

        System.out.println("ABA问题的解决----------------");
        new Thread(() -> {
            int stamp = atomicStampedReference.getStamp();
            System.out.println(Thread.currentThread().getName() + "     第一次版本号：" + stamp);
            try {
                TimeUnit.SECONDS.sleep(1);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            atomicStampedReference.compareAndSet(100, 101,stamp = atomicStampedReference.getStamp(),stamp = atomicStampedReference.getStamp() + 1);
            System.out.println(Thread.currentThread().getName() + "     第2次版本号：" +  atomicStampedReference.getStamp());
            atomicStampedReference.compareAndSet(101, 100, atomicStampedReference.getStamp(), atomicStampedReference.getStamp() + 1);
            System.out.println(Thread.currentThread().getName() + "     第3次版本号：" +  atomicStampedReference.getStamp());
        },"t3").start();

        new Thread(() -> {
            int stamp = atomicStampedReference.getStamp();
            System.out.println(Thread.currentThread().getName() + "     第一次版本号：" + stamp);

            try {
                TimeUnit.SECONDS.sleep(3);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            boolean b = atomicStampedReference.compareAndSet(100, 2019,  stamp,  stamp + 1);
            System.out.println(Thread.currentThread().getName() + "     是否修改成功:" + b + "     最新版本号：" + atomicStampedReference.getStamp());
            System.out.println(Thread.currentThread().getName() + "     最新：" +  atomicStampedReference.getReference());

        },"t4").start();


    }
}
